Heating, Air Conditioning, Fridge, HVAC/Clanging/Rattling noise


The outside AC unit is making a loud, random clanging/rattling noise while the fan is operating.  It is a metal on metal sound and there is not pattern to it.  When I look inside I do see a long, thin metal piece sticking out from the side but it's below the fan.  Perhaps that gets swept up into the fan blade by the updraft?  Also, the noise doesn't always happen.  I put the unit on last night and the noise didn't happen when the repairman was here.  Good timing :o)  Anyway, any hints you could provide would be appreciated.  Have a great day.


If this is a Heat Pump, and you live in a snow climate , possible ice is freezing a a fan blade throwing the balance of, short of tightening all the sheetmetal panels,and outdoor motor support brackets,your fan blades may not be aligned dead vertical ,try free spinning the outdoor fan blade and notice if it's closer to the frame than the opposite side, basically the fan blade ends should be somewhere around 1/2" from the frame, uniform all the way around.Possible the motor bearings are going, ( if a ball bearing motor ) Not sure what you are describing when you say "a long thin metal piece sticking out from the side but it's below the fan " unless that is where they ran the outdoor motor wires through a conduit, which is a common practice, usually that piece is hard plastic.

Heating, Air Conditioning, Fridge, HVAC

All Answers

Answers by Expert:

Ask Experts




40+ years diversified experience.An HVAC/Refrigeration Self Employed Contractor since 1986. NATE Certifield. Answer questions pertaining to Residential and Commercial Air Conditioning , Warm Air Heating, Heat Pump systems.Mechanical and Electrical troubleshooting of these systems.Be as detailed as possible when describing problem.Packaged unit or split systems.No appliance questions.


Installation and Troubleshooting, Mechanical and Electrical, in following areas, Refrigeration ( Walk In and Reach In Coolers and Freezers ) Commercial Roof Top and Packaged Heating/Cooling ( Natural Gas,Propane, Electric, and Heat Pumps ) Computer Room Air Conditoning Systems,Commercial Residential Packaged and Split Systems Air Conditoning and Heat Pumps.Warm Air Oil , Natural and Propane Gas Heating systems.

Graduated from Private Technical School in 1975. An HVAC/Refrigeration Contractor . Have Unlimited Heating/Piping and Cooling Contractor License.Limited Sheetmetal Contractors License.NATE Certifield. York Certifield Master Heat Pump Technician 1986. Served 33 years combination Active Duty Air Force , Air Force Reserves and Air National Guard in the HVAC/Refrigeration Shop/Mechanical Shop. Troubleshooting/Installing HVAC/Refrigeration Equiptment Worldwide. Retiring in 2003 as a Senior NCO ,and a Mechanical Superintendent.

©2017 About.com. All rights reserved.